Adverse reactions to tetanus toxoid

Clinical Decision Support Reduces Unnecessary Tetanus Vaccinations in the Emergency Department

STUDY OBJECTIVE

Tetanus is the most common vaccination given in the emergency department; yet, administrations of tetanus vaccine boosters in the ED may not comply with the US Centers for Disease Control and Prevention's recommended vaccination schedule. We implemented a clinical decision support alert in the electronic health record that warned providers when ordering a tetanus vaccine if a prior one had been given within 10 years and studied its efficacy to reduce potentially unnecessary vaccines in the ED.

METHODS

This was a retrospective, quasi-experimental, 1-group, pretest-posttest study in 3 hospital EDs in Boston, MA. We studied adult patients for whom tetanus vaccines were ordered despite a history of vaccination within the prior 10 years. We compared the number of potentially unnecessary tetanus vaccine administrations in a baseline phase (when the clinical decision support alert was not visible) versus an intervention phase.

RESULTS

Of eligible patients, 22.1% (95% confidence interval [CI] 21.8% to 22.4%) had prior tetanus vaccines within 5 years, 12.8% (95% CI 12.5% to 13.0%) within 5 to 10 years, 3.8% (95% CI 3.6% to 3.9%) more than 10 years ago, and 61.3% (95% CI 60.9% to 61.7%) had no prior tetanus vaccination documentation. Of 60,983 encounters, 337 met the inclusion criteria. A tetanus vaccination was administered in 91% (95% CI 87% to 96%) of encounters in the baseline phase, compared to 55% (95% CI 47% to 62%) during the intervention. The absolute risk reduction was 36.7% (95% CI 28.0% to 45.4%), and the number of encounters needed to alert to avoid 1 potentially unnecessary tetanus vaccine (number needed to treat) was 2.7 (95% CI 2.2% to 3.6%). For patients with tetanus vaccines within the prior 5 years, the absolute risk reduction was 47.9% (95% CI 35.5 % to 60.3%) and the number needed to treat was 2.1 (95% CI 1.7% to 2.8%).

CONCLUSION

A clinical decision support alert that warns ED clinicians that a patient may have an up-to-date tetanus vaccination status reduces potentially unnecessary vaccinations.

Arthus Reaction as an Adverse Event Following Tdap Vaccination

Repeat administration of tetanus toxoid-containing vaccines has rarely been associated with Arthus phenomenon, an immune-complex reaction. In the US, since 2013, tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccines (Tdap) have been recommended for administration during each pregnancy. Separately, in 2019, one Tdap was approved for repeat administration in adults in the US. We aimed to describe trends in spontaneously reported Arthus reactions following Tdap in the US and to assess the risk of this phenomenon in persons receiving Tdap repeatedly. We reviewed Arthus reports in the Vaccine Adverse Events Reporting System (VAERS), 1990-2018. Reporting rates were estimated using Tdap doses distributed data. A systematic literature review was conducted in MEDLINE for any Arthus cases reported in Tdap clinical trials and observational studies published between 2000 and 2019. We found 192 Arthus reports in VAERS after any vaccine, of which 36 occurred after Tdap and none were reported during pregnancy. The Arthus reporting rate was estimated at 0.1 per million doses distributed. We identified eight published studies of Tdap administration within five years after a previous dose of tetanus toxoid-containing vaccine; no Arthus cases were reported. We conclude that Arthus reaction following Tdap is extremely rare. Increasing frequency of repeat Tdap administration in adults in the US did not result in a detectable increase in reporting rates of this phenomenon, confirming the favorable safety profile of Tdap.

The vaccines-associated Arthus reaction

The Arthus reaction is a rare adverse reaction that usually occurs after vaccination with large and more severe local reactions, belonging to type Ⅲ hypersensitivity reaction. This reaction is characterized by pain, swelling, induration (Tissue that becomes firm) and edema, even accompanied by severe necrosis or ulceration at the injection sites. However, most of mild cases generally can be cured without treatment, and only severe cases need to be treated with anti-allergy. Therefore, this adverse reaction is often ignored by people.We searched PubMed, Web of Science and Chinese database (CNKI database and Wan Fang database) for published studies using the terms "Arthus reaction" or "Arthus phenomenon", combined with "vaccine", with no date or language restrictions for all publications before January 28, 2019. Only 30 cases of Arthus reaction were found, of which only one case died.4 cases of Arthus reaction post-dose-1 were reported in the review. The proportion of Arthus reaction occurred after the first, second and third injections in those case reports was 13.3%, 50.0%, and 23.3%, respectively. Arthus reaction was determined according to the clinical symptoms (The symptoms which were observed by the researchers, such as red, swelling and painful with itching at or around the injection sites). The specific causes of Arthus reaction after one dose of vaccination are not described in detail in literatures. Therefore, it could be hypothesized that the case has a pre-existing specific IgG (Such as pre-existing antibody, etc.) to cause the Arthus reaction.And 17 reported cases were observed in children younger than 6 y. In addition, we collected only 18 cases of bacterial vaccine-induced Arthus reaction and 12 cases of viral vaccines. However, there are no other data (Such as the total number and incidence rate of vaccination) in literatures, so we cannot compare statistically significant differences. At presents, no previous reviews of vaccine-induced Arthus reaction have been found. Thus, a systematic review about vaccine-associated Arthus reaction is urgently needed to deepen people's understanding and concern of this phenomenon. In this manuscript, we retrospectively reviewed the description of the discovery process and mechanisms of Arthus reaction, a description of the characteristics of Arthus reaction cases, reporting the Arthus reaction cases in China during 2010-2015, diagnostic criteria and general treatment, preventive measures of Arthus reaction, and challenges remaining to be investigated in the future.

[Research and development of the free radical scavenger edaravone as a neuroprotectant]

Increasing data suggest that oxygen free radical species play detrimental roles in ischemic diseases. A free radical scavenger capable of inhibiting oxidative injury is expected to become a new drug for the treatment of ischemic diseases such as cerebral ischemia. Edaravon (3-methyl-1-phenyl-2-pyrazolin-5-one), which has been developed as an neuroprotective agent for more than 15 years since its discovery, is approved for the treatment of acute cerebral infarction. In this paper, the pharmacologic characteristics and clinical effects of edaravone are reviewed. In early stage of investigation, edaravone was found to have promising activities as an antioxidative radical scavenger, quenching hydroxyl radical (.OH) and inhibiting both .OH-dependent and .OH-independent lipid peroxidation. Edaravone showed inhibitory effects on both water-soluble and lipid-soluble peroxyl radical-induced peroxidation systems, which are different from the inhibitory effects of vitamins C and E in each system, respectively. Oxidative injury to cultured endothelial cells caused by arachidonate (AA) peroxides is prevented in the existence of edaravone. To clarify the characteristics of this free radical scavenger, further investigation was carried out. Edaravone ameliorated exacerbation of cortical edema induced by a focal ischemia-reperfusion model in rats, suggesting inhibitory effects on oxidative injury to the blood-brain barrier (BBB). Additionally, edaravone also prevented rat cortical edema caused by intracortical AA infusion in which free radical production and subsequent oxidative injury to the BBB are involved. With advances in in vivo measurement technology of oxygen radicals, edaravone was shown to inhibit postischemic increases in .OH production and tissue injury in the penumbral or recirculated area in rat cerebral ischemia models. In clinical studies, edaravone improved the core neurologic deficits, activities of daily living, and functional outcome of stroke patients. Furthermore, a study using proton magnetic resonance spectroscopic techniques showed that edaravone preserved N-acetyl-aspartate in stroke patients, a promising neuronal marker in the brain. Further investigation is essential for a better understanding of free radical-mediated cerebral injury during ischemia followed by recirculation. We hope that edaravone represents a promising neuroprotectant for drug therapy in acute cerebral ischemia.

Serum antibodies to diphtheria-tetanus-pertussis vaccine components in Argentine children

The Argentine vaccination schedule against diphtheria, tetanus and pertussis (DTP) recommends three doses of DTP vaccine at 2, 4 and 6 months of age, two boosters at 18 months and 6 years, a booster dose of tetanus vaccine every 10 years and two doses during pregnancy. To evaluate the effect of this schedule, antibodies against pertussis toxin (PT) and filamentous hemagglutinin (FHA) and against tetanus and diphtheria toxoids were determined by ELISA in serum samples from children (1 month to 6 years) who received different doses of DPT vaccine: 0 dose (n = 50), 1 dose (n = 25), 2 doses (n = 25), 3 doses (n = 55), first and second booster (n = 25); 25 pregnant women and their offspring, and 45 adults. High antibody levels against PT (> 140 EU/ml) and FHA (> 80 EU/ml) were recorded in mothers and in the newborn. Antibody titers against PT increased with the number of doses given and decreased with time. Full protection against tetanus (titers > 0.1 IU/ml) was observed in the group of adults (0.37 IU/ml), in mothers (4.4 IU/ml) and their newborn offspring (5.5 IU/ml), and in children after receiving the second dose of DTP vaccine (1.86 IU/ml). The immune status for diphtheria was far lower, as most of the groups lacked adequate protection. After the third dose of DTP vaccine, only 78% of the children had antibody titers above the protective level (0.1 IU/ml). Since antibody levels considered to provide full protection were only achieved after the first booster dose of DTP vaccine, the primary three-dose schedule seems to be insufficient to confer adequate immunity in all vaccinees. Because of the high proportion of non-protected adults, a booster dose of Td vaccine should be considered for this group.